The present invention relates to a multicolor thermal transfer recorder and more particularly to the initial setting of an ink film therein.
The multicolor thermal transfer recorder shown in FIG. 1 is a typical recorder performing multicolor recording, the construction thereof will be described hereinunder. Reference numeral 1 denotes a platen on which a recording medium 2 is arranged in a predetermined state. The platen 1 is adapted to feed on the recording medium 2 at a predetermined pitch.
Reference numeral 3 designates an ink film which is pressed between a thermal head 4 and the recording medium 2, and the transfer recording onto the recording medium 2 is performed by means of a head carrier member 5 which generates heat at a predetermined timing while moving in the direction of the arrow X. Reference numeral 6 denotes a supply reel for supplying the ink film 3. The used ink film 3 is taken up in the direction of the arrow a by means of a take-up reel 7. FIG. 2 shows the construction of the ink film. The ink film is coated with yellow 3Y, magenta 3M and cyan 3C consecutively in sequence. The range indicated by the arrow b is the range in the main scanning direction, i.e., the movement range of the head carrier member and the thus maximum recording width. In this case, when the recording medium 2 and the ink film 3 are fixed, after the head carrier member 4 has scanned, for example, the yellow part 3Y which has been recorded, the ink film 3 is fed on by the supply reel 6 until the magenta part 3M thereof is set on the recording medium and, at the same time, the yellow part 3Y is taken up by the take-up reel 7, and then the head carrier member 4 carries out a second scanning. Similarly, the cyan part 3C is scanned by a third scanning. Thus, dots for one line are recorded in multiple colors, and the recording medium 2 is fed on by one pitch in the direction of the arrow Y. Then, in a similar manner, the recording for the next line is carried out. In general, in a multicolor thermal transfer recorder employing three primary colors for a subtractive color process as described above, scanning the colors in the order of yellow, magenta and cyan makes it possible to provide other colors by combinations of the primary colors which have excellent running, brightness, saturation, etc., characteristics.
As described above, in a multicolor thermal transfer recorder of this type, since a plurality of inks in a plurality of colors have been applied consecutively in sequence, when the power to the recorder is turned on, it is necessary that the operator confirms that the yellow part of the ink film is set on the platen so as to cover the recording width completely, if the recording width is not covered completely by the yellow part, the ink film must be fed on until the yellow part is set properly on the platen. Alternatively, the initial setting of the yellow part is generally effected by carrying out an initial feed of the ink film up to the next application of a yellow part, without any confirmation. In such a case, the probability increases that the initial feed will waste a maximum of the ink film for one line. As the number of times of turning on and off the power increases, the labor required for the former initial operation increases unfavorably, and in the latter initial operation, the amount of ink film wasted compared with an identical roll increases disadvantageously.
An object of the present invention is to eliminate the need for supervision, as well as reduce the probability that ink film will be wasted, by judging, when turning on the power, whether or not the recording width is covered by the yellow part and whether or not an initial feed is necessary, by providing a plurality of means for detecting colors at positions separated from each other, thereby removing the above disadvantages.